North America's largest steel mill has a plan to reduce emissions and it's a perfect example of why carbon capture is so controversial

• US Steel's plant in Gary, Indiana, aims to deploy carbon capture to reduce its carbon footprint by 2026.
• The technology will capture 0.5% of the steel mill's carbon dioxide emissions.
• Climate groups and some scientists say carbon capture is unproven and will worsen global warming.

A more-than-century-old steel mill in Gary, Indiana, plans to be a testing ground for a controversial climate technology.